Health authorities in some European countries – including Germany – are facing resistance to the vaccine after side-effects led hospital staff and other front-line workers to call in sick, putting extra strain on already-stretched services.

In a statement retweeted by Health Minister Jens Spahn, the Paul Ehrlich Institute (PEI) said the vaccine “prevents COVID-19 disease in the majority of cases or alleviates symptoms when disease occurs.”

“Vaccine reactions occur relatively frequently after administration of the vaccine. But they are short-lived and usually reflect the body’s normal immune response to vaccinations,” it added.

The PEI said it had been notified of reports from some clinics of increased sickness among personnel given the AstraZeneca vaccine, with reactions including fever, chills, headache, muscle and limb pain, and a general feeling of illness.

The Institute said clinical trials of the vaccine had shown “reactions usually occur shortly after vaccination and are not associated with more severe or prolonged illness.”

Spahn responded on Wednesday to reports that essential workers were reluctant to receive the AstraZeneca shot after some experienced strong side-effects, saying it was both safe and effective.

“I would be vaccinated with it immediately,” Spahn told reporters. (Writing by Paul Carrel; editing by Jonathan Oatis)